Tumor Paint? products for real-time intraoperative visualization of solid tumors are designed to enable more complete resection while sparing surrounding normal tissue. The Tumor Paint BLZ-100 is a peptide-fluorophore conjugate that specifically binds to multiple solid tumor types and fluoresces in the near-infrared range, minimizing light scatter and signal attenuation. In a Phase I study of BLZ-100 in dogs with a variety of tumor types, soft tissue sarcomas were the tumor type labeled with the highest fluorescence intensity, best tumor to background ratio, and highest sensitivity and specificity. In humans, soft tissue sarcomas represent an orphan indication with very high unmet need. A Phase 1 clinical trial of BLZ-100 in humans with soft tissue sarcoma is proposed for Phase II. Patients undergoing tumor resection will receive BLZ-100 intravenously 1-7 days before surgery, and tissue will be imaged intraoperatively and ex vivo after surgery. Technical objectives are to demonstrate that BLZ-100 recognizes soft tissue sarcoma in humans, to demonstrate that these tumors can be distinguished from surrounding normal tissue during surgery, and to determine the optimal dose and imaging interval. This study will demonstrate BLZ-100 safety and imaging efficacy in human sarcoma and will provide clinical experience with intraoperative near-infrared imaging.